It may sound strange, but there is some science behind these animal-based add-ons. Horse oil is sterile and well-known for how absorbent it can be, so there isn’t any greasy residue. Pure horse oil is also edible (it’s additive-free) and high in unsaturated fats. And in case you need more ways to sway you, horse oil has been used for years to heal burns.

As for donkey milk, it is rich with vitamin C (four to five times the vitamin C in cow’s milk) and has a lot of rumoured fans throughout history.

Refinery 29 spoke with makeup artist Napoleon Perdis about the newly trendy dairy, and he says he did some research into it “after learning Egyptian queen Cleopatra had reportedly bathed in donkey milk for its youth-enhancing effects.” In fact, the rumour is that it took the milk of 700 asses for her daily bath. Other alleged proponents of donkey milk include Pauline Bonaparte and Emperor Nero’s second wife.

And as if these two animal-based ingredients weren’t enough, pig collagen is also a Korean beauty trend that is on the rise. Holika Holika has a “Pig Collagen Jelly Pack” that requires 70,000 mL of collagen (taken from pig skin), and claims to remove wrinkles and refresh skin.